x86/mtrr: convert use_intel_if u32 to bool

This field is always only 1 currently but may allow 0 in the future so
convert it to a bool to provide proper range checking by the compiler.

Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/cpu/mtrr/generic.c

@@ -560,7 +560,7 @@ static int generic_have_wrcomb(void)
 /* generic structure...
  */
 const struct mtrr_ops generic_mtrr_ops = {
-	.use_intel_if      = 1,
+	.use_intel_if      = true,
 	.set_all	   = generic_set_all,
 	.get               = generic_get_mtrr,
 	.get_free_region   = generic_get_free_region,

xen/arch/x86/cpu/mtrr/mtrr.h

@@ -9,7 +9,7 @@
 
 struct mtrr_ops {
 	u32	vendor;
-	u32	use_intel_if;
+	bool	use_intel_if;
 //	void	(*init)(void);
 	void	(*set)(unsigned int reg, unsigned long base,
 		       unsigned long size, mtrr_type type);
@@ -39,7 +39,7 @@ extern u64 size_or_mask, size_and_mask;
 extern const struct mtrr_ops *mtrr_if;
 
 #define is_cpu(vnd)	(mtrr_if && mtrr_if->vendor == X86_VENDOR_##vnd)
-#define use_intel()	(mtrr_if && mtrr_if->use_intel_if == 1)
+#define use_intel()	(mtrr_if && mtrr_if->use_intel_if)
 
 extern unsigned int num_var_ranges;